# gst art: an image of chaotic hydrodynamics, by "Leo"

<< One of the first to visualize these flows was scientist, artist, and engineer Leonardo da Vinci, who combined keen observational skills with unparalleled artistic talent to catalog turbulent flow phenomena. Back in 1509, Leonardo was not merely drawing pictures. He was attempting to capture the essence of nature through systematic observation and description. In this figure,  https://cdn.arstechnica.net/wp-content/uploads/2018/10/daVinciWake.png   we see one of his studies of wake turbulence, the development of a region of chaotic flow as water streams past an obstacle. >>

Lee Phillips. Turbulence, the oldest unsolved problem in physics. The flow of water through a pipe is still in many ways an unsolved problem. Oct 10, 2018.

https://arstechnica.com/science/2018/10/turbulence-the-oldest-unsolved-problem-in-physics/

# gst: the interaction time to distinguish self and non-self

<< The Freiburg experiments supports the theory that T cells distinguish self and non-self, pathogenic molecules on the basis of the interaction time. >>

A question of time. University of Freiburg. May 3, 2019

https://www.eurekalert.org/pub_releases/2019-05/uof-aqo050319.php

Yousefi OS, Günther M, et al. (2019) Optogenetic control shows that kinetic proofreading regulates the activity of the T cell receptor. eLife. doi: 10.7554/eLife.42475.

https://elifesciences.org/articles/42475

# evol: hanging by a rope off a cliff, the vibrant pigments of bird feathers to trace the mechanics of evolution

<< All organisms depend on input of exogenous compounds that cannot be internally produced. Gain and loss of such dependencies structure ecological communities and drive species’ evolution, yet the evolution of mechanisms that accommodate these variable dependencies remain elusive. (AA) show that historical cycles of gains and losses of external dependencies in avian carotenoid-producing networks are linked to their evolutionary diversification. >>

Alexander V. Badyaev, Alexander B. Posner, et al. Cycles of external dependency drive evolution of avian carotenoid networks. Nature Communications volume 10, Article number: 1596 Apr 8, 2019.

https://www.nature.com/articles/s41467-019-09579-y

<< Think about hanging by a rope off a cliff. With one rope, if it disappears, you die. If you have two and one fails, you get to live. But having a third safety rope allows enough stability that you can make something out of the first two - like a ladder - and thus take control of your trajectory while the stability lasts, >> Alexander Badyaev.

What the vibrant pigments of bird feathers can teach us about how evolution works. University of Arizona. Apr 24, 2019.

https://www.eurekalert.org/pub_releases/2019-04/uoa-wtv042419.php

# ai.bot: "Machine Behaviour", the multi-disciplinary, ethological approach to "Intelligent Machines", by MIT

<< Rather than simply being scared of "intelligent machines," (..) society needs to study algorithms with a multi-disciplinary approach akin to the field of ethology. >>

Tiernan Ray. MIT finally gives a name to the sum of all AI fears. Apr 25, 2019.

https://www.zdnet.com/article/mit-finally-gives-a-name-to-the-sum-of-all-ai-fears/

<< Machines powered by artificial intelligence increasingly mediate our social, cultural, economic and political interactions. >>

AA << first outline a set of questions that are fundamental to this emerging field and then explore the technical, legal and institutional constraints on the study of machine behaviour. >>

Iyad Rahwan, Manuel Cebrian, et al. Machine behaviour. Nature volume 568, pages477–486 Apr 24, 2019.

https://www.nature.com/articles/s41586-019-1138-y

Also

anomalous formation of molecules after vapor deposition. Dec 31, 2015

http://flashontrack.blogspot.com/2015/12/rmx-s-gst-anomalous-formation-of.html 

# phys: to move (momentarily) in and out of existence by extracting something from nothing

<< According to Einstein, nothing can travel faster than light in vacuum. Because of this, it is usually assumed that the Cherenkov emission cannot occur in vacuum. But according to quantum theory, the vacuum itself is packed full of "virtual particles", which move momentarily in and out of existence. These ghostly particles are usually not observable but, in the presence of extremely strong electric and magnetic fields, they can turn the vacuum into an optical medium where the speed of light is slowed down so that high velocity charged particles can emit Cherenkov gamma rays. This is totally unexpected in a vacuum. >>

Extracting something from nothing: A bright glow from empty space.
University of Strathclyde. Apr 25, 2019.

https://www.eurekalert.org/pub_releases/2019-04/uos-esf042519.php

Alexander J. Macleod, Adam Noble, Dino A. Jaroszynski. Cherenkov Radiation from the Quantum Vacuum.  Phys. Rev. Lett. 122, 161601 Apr 24,  2019.

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.122.161601

# age: apropos of flatworm regeneration (2)

AA << have developed a computational model of planarian (flatworm) regeneration that explains how fragments of planaria determine which end should form a tail and which should form a head. >>

Scientists unlock new role for nervous system in regeneration. Tufts  University. Apr 25, 2019.

https://www.eurekalert.org/pub_releases/2019-04/tu-sun042519.php

<< Uniquely, [AA] model explains the various head-tail patterning outcomes of a wide range of molecular and physiological manipulations. Testing the novel predictions of this model revealed the nervous system as an instructive regulator of axial patterning. >>

Alexis Pietak, Johanna Bischof, et al.  Neural control of body-plan axis in regenerating planaria. PLoS Comput Biol 15(4): e1006904. Apr 16, 2019. doi:10.1371/journal.pcbi.1006904

https://journals.plos.org/ploscompbiol/article?id=10.1371/journal.pcbi.1006904

Also

# age: apropos of flatworm regeneration. Apr 2, 2019

https://flashontrack.blogspot.com/2019/04/age-apropos-of-flatworm-regeneration.html

# behav: to change moral decisions (between 'guilt aversion’ and 'inequity aversion) depending on the context.

AA << find markedly different neural substrates for the strategies of "guilt aversion’ and 'inequity aversion", even under conditions where the two strategies produce the same choices.  >>

AA << also identify a new strategy, 'moral opportunism', in which participants adaptively switch between guilt and inequity aversion, with a corresponding switch observed in their neural activation patterns. These findings provide a valuable view into understanding how different individuals may utilize different moral principles. >>

Jeroen M. van Baar, Luke J. Chang,  Alan G. Sanfey. The computational and neural substrates of moral strategies in social decision-making.  Nature Communications. volume 10, Article number: 1483 (2019)

https://www.nature.com/articles/s41467-019-09161-6

How do we make moral decisions?
New study shows how your moral behavior may change depending on the context. Dartmouth College. Apr 18, 2019.

https://www.eurekalert.org/pub_releases/2019-04/dc-hdw041819.php